Shock absorber structure including flexible bladder means

ABSTRACT

A vehicle shock absorber for dampening spring oscillations on a vehicle having a pair of bladders located in a casing and separated by a dividing member. The shock absorber may be attached between the body of a vehicle and its wheel suspension, whereby movement of the wheel suspension will move the dividing member between the bladders against one or the other bladder forcing a fluid in the bladders to flow therebetween through a bladder connecting member. A valve allows the fluid to flow easier in one direction than the other, or the valve may be eliminated by the choice of bladder material and design whereby a shock absorber is provided which may be of tubular design without having the usual fluid seals.

United States Patent 1191 Valdespino 1 51 Aug. 14, 1973 SHOCK ABSORBERSTRUCTURE INCLUDING FLEXIBLE BLADDER MEANS [76] Inventor: Joseph M.Valdespino, 5(123 Golf Club Parkway. Orlando, Fla. 32808 [22] Filed:Dec. 29, 1971 [21] Appl. N0.: 213,473

[52] US. Cl 188/281, 188/298, 188/322 [51] Int. Cl F161 9/18 [58] Fieldof Search 188/281, 298, 313, 188/314, 315, 322; 267/64 [56] ReferencesCited UNITED STATES PATENTS 2,317,028 4/1943 Chappell et al.... 188/298X 1,519,451 12/1924 Harris 188/313 X 1,572,484 2/1926 Homar 188/3132,943,711 7/1960 Rossman 188/322 3,013,816 12/1961 lsham 188/298 XPrimary E.\'an1iner-George E. A. Halvosa AttorneyDuckworth & Hobby 5 7ABSTRACT A vehicle shock absorber for dampening spring oscillations on avehicle having a pair of bladders located in a casing and separated by adividing member. The shock absorber may be attached between the body ofa vehicle and its wheel suspension, whereby movement of the wheelsuspension will move the dividing member between the bladders againstone or the other bladder forcing a fluid in the bladders to flowtherebetween through a bladder connecting member. A valve allows thefluid to flow easier in one direction than the other, or the valve maybe eliminated by the choice of bladder material and design whereby ashock absorber is provided which may be of tubular design without havingthe usual fluid seals.

7 Claims, 9 Drawing Figures m/vs/v TOR.

Arrr's.

Patented Aug. 14, 1973 2 Sheets-Sheet 1 Joseph M Va/desp/no AM aPatented Aug. 14, 1973 2 Sheets-Sheet 3 INVENTOR. Joseph M. Va/desp/hoSHOCK ABSORBER STRUCTURE INCLUDING FLEXIBLE BLADDER MEANS BACKGROUND OFTHE INVENTION The present invention relates to shock absorbers andespecially to a shock absorber for dampening spring oscillations in thesuspension system of vehicles while eliminating seals used to preventthe loss of a fluid in the shock absorber.

Vehicle shock absorbers are commonly used between the body of a vehicleand the wheel suspension for dampening the objectionable springoscillations resulting from movement of the wheel over a road surface.Most modern day shock abosrbers are of the hydraulic type having apiston moving inside a cylinder and forcing oil through small openingsto create high resistance to the movement of a piston thereby dampeningthe oscillations of the spring. Older vehicles used a shock absorberhaving a piston that travels in a transverse manner in an oil filledcasing and having the piston connected to the axle of the vehiclethrough a lever system. However, the type of shock absorber mostcommonly used nowadays is frequently referred to as the telescopic shockabsorber and has a pair of tubes, one fitting inside the other with apiston rod being connected to the outer tube so that the piston moves inan oil filled inner chamber of the inner side tube. The piston normallycontains a pair of check-valves which alternately allow the hydraulicfluid to pass in one direction only. It is desirable that the upwardmovement must be only slightly damp in order not to impair the springaction, and therefore a valve with a larger orifice is accordingly usedto allow the hydraulic fluid to escape quickly so that only smalldamping is obtained. On the other hand, the return motion of the springof the vehicle must be clamped to a much greater extent and for thisreason a much narrower orifice is used for the other valve which openswhen the piston travels in the opposite direction, whereby the shockabsorber intensity of damping in each direction is substantiallydifferent. This type of prior art shock absorber has workedsatisfactorily but has generally required replacement after a period oftime due to wearing of the seals which prevent fluid from escapingaround the piston rod and thus allowing some fluid to escape, reducingthe effectiveness of the shock absorber.

It is accordingly one object of the present invention to provide a shockabsorber without requiring seals and adapted to have a longer life whilebeing economical to manufacture for replacement of existing shockabsorbers.

In the past, a number of systems have been provided for producing fluidactuated springs or hydraulic shock absorbers utilizing expandablesections. One such device is seen in U. S. Pat. No. 3,151,856 forI-IERMETI- CALLY SEALED LIQUID SPRINGS utilizing a pair of bellowsflowing from one to the other through a chamber passing through thepiston rod. This system, however, provides a piston to move to and froin the hydraulic fluid and requires delicate attachment of thedeformable sections to the rigid casing. Another HY- DRO-PNEUMATICSUSPENSION DEVICE can be seen in U. S. Pat. No. 3,331,601, havingannular control diaphragms connected at predetermined points within asuspension device for expanding and collapsing against the walls of thedevice. Other devices using flexible containers and suspension devicescan be seen in U.S. Pat. No. 2,256,835, for OLEOPNEUMATIC DEVICE; U.S.Pat. No. 3,410,549, for a VEHICLE SUSPENSION system having anaccumulator for compressed gas; U.S. Pat. No. 3,206,185 for a SUSPEN-SION SYSTEM AND APPARATUS FOR SUPPORT- ING A STRUCTURE, having aflexible boot and a cylindrical flexible diaphragm therein, utilizing acombination of gas and oil and requiring seals therein; U.S. Pat. No.2,688,150 for a VARIABLE VOLUME CHAMBER, providing for a dampeningsystem having a yielding seal chamber or bladder therein; and U.S. Pat.No. 3,226,103 for a FLUID SPRING AND SHOCK ABSORBER having a collapsibleair bag for separating a compressed air chamber from the remainingportions of a chamber.

SUMMARY OF THE INVENTION The present invention relates to vehicle shockabsorbers especially those shock absorbers for dampening springoscillations between the vehicle body and the wheel suspensions. Acasing is provided which may be tubular shaped and has a bladder locatedat each end enclosing a predetermined amount of liquid in each bladder.The bladders are flexible or collapsible and are connected to each otherby a tube, or the like, so that the fluid may flow from one bladder tothe other. A dividing member is located between the bladders and isconnected to the vehicle at one point, while the casing is attached tothe vehicle at a second point so that movement of the vehicle suspensionrelative to the vehicle body will move the dividing member relative tothe casing, thus driving the bladder dividing member against one of thebladders collapsing it and driving the fluid therein into the otherbladder expanding the other bladder. A valve located in the connectingtube between the bladders allows the fluid to flow more freely in onedirection than the other, whereby the dividing member between thebladders is damped more in one direction than in the second. The casingmay be lined on the interior with teflon to prevent wear on the bladdersduring the operation of the shock absorbers, and means are provided forincreasing or decreasing the dampening action of the shock absorber. Oneembodiment provides a pair of bladders not requiring a connecting tubeand valve by the selection of bladders having different intensities ofdamping.

BRIEF DESCRIPTION OF THE DRAWINGS Other objects, features and advantagesof this invention will be apparent from a study of the writtendescription and the'drawings, in which FIG. 1 is a cutaway sectionalview of a shock absorber in accordance with the present invention;

FIG. 2 is a side sectional view of the shock absorber of FIG. 1 in asecond operating condition;

FIG. 3 is a sectional view taken along line 33 of FIG. 2;

FIG. 4 is a side sectional view ofa section of the connecting tubebetween the bladders of the shock absorber of FIGS. 1-3;

FIG. 5 illustrates a section of the connecting tube between the bladderswith means for restricting the passage of fluid therethrough;

FIG. 6 shows a cutaway side sectional view of another embodiment of thepresent invention;

FIG. 7 shows a side sectional view of another embodiment;

FIG. 8 shows a sectional view of the casing of the embodiment inaccordance with FIG. 7; and

FIG. 9 is a cutaway sectional view of another embodiment of the presentinvention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to FIG. 1 of thedrawings, there is seen a shock absorber 10 having a bladder 11 and abladder 12 located inside of casing 13. The bladder 11 is shown as beinggenerally donut or annular shaped to allow a rod 14 to passtherethrough. Rod 14 is connected to a bladder dividing member 15 andhas an attaching member 16 on the other end thereof, and passes throughthe casing 13 at an opening and guide bushing 17. Casing 13 also has anattaching member 18 fixedly attached to the opposite end of attachingmember 16 so that either member 16 or 18 can be attached to the wheelsuspension with the other attaching member being attached to the vehiclebody for dampening the action of the spring of the vehicle while thevehicle rides over a bump or uneven portion of a road, or the like.Bladders 11 and 12 may be made of any flexible material desired such asa surgical rubber, neoprene, or the like, so long as the material isadapted to collapse and re-expand over long periods of time withoutfracture. The upper bladders 11- are illustrated having an interiorportion 20 which is thicker than the exterior portion 21 for providing abetter collapsing action thereof. Tube 23 connects bladders 11 and 12together for allowing fluid in the otherwise sealed bladders to flowtherebetween, and a valve 24 connected to the tube 23 allows fluid to beadded or taken away from the shock absorber without otherwise damagingthe shock absorber. It should also be noted that a feature of thepresent invention provides the inner surface 25 to be coated with asolid lubricant such as Teflon so that the bladders l1 and 12 will notbe damaged through excessive abrasion between the bladders and the wallsof the casing 13. FIG. I has the dividing member 15 being driven againstthe bladder 11 thereby collapsing a portion of this bladder and drivingthe fluid into bladder 12 which is shown fully expanded, while FIG. 2has the bladder 11 fully expanded having driven the fluid from bladder12 which is partially collapsed.

It should of course be realized that any type of fluid desired could beused including gases or liquids, but inasmuch asgas offers a reducedresistance in its flow, a liquid has generally been preferred.

Referring now to FIG. 3, a cross section of the shock absorber 10 isillustrated having the casing 13 surrounding the bladder 11 which has aninner surface 20 allowing the rod 14 to to ride therethrough and alsohas a connection tube 23 connected to the bladder through the walls ofthe casing 13.

In FIG. 4, a tube 23 can be seen as having a check or flat valve 26therein which valve is adapted to allow the fluid to flow by opening inone direction, and when closed, in the second direction. A small opening27 in the flap or check portion of the valve allows much more limitedflow in the opposite direction.

FIG. 5 shows a cutaway portion of the valve 24 for adding or removingfluid from the system and also of another cock-type valve 28 having ahandle 30 which may be rotated to reduce the passage 31 through tube 23to vary the action of the shock absorber in both directionssimultaneously by screwing the closure portion 32 into andout of thevalve section.

Turning now to FIGS. 6 through 9, several embodiments of a shockabsorber in accordance with the present invention are illustrated inwhich FIG. 6 has a shock absorber havlng a casing 41 which is tubular inshape and with a shaft 42 passing through an opening and .guide bushing43. The casing has a shaft 44 connected to the opposite end from shaft42 and has a connecting means 45 for connecting the shock absorber atone end to one portion of the vehicle. Shaft 42 extends into the casing41 through an annular bladder 46 which has a thicker interior portion 47than the exterior portion. Shaft 42 connects to a disc member 50 whichin turn has a shaft 51 connecting it to a smaller disc 52 which is heldagainst a second bladder 53, so that disc 50 engages the bladder 46while disc 52 engages the bladder 53. The bladders are interconnected bya flexible hose 54 passing through disc 50 and disc 52 which allows thegas or liquid located in bladders 46 and 53 to pass between each otheras the shaft 52 forces the discs 50 and 52 up and down within the casing41. A valve member 55 may also be provided for adding or removing gasfrom the bladders 46 and 53 and a valve may be placed either in theopening 56 in disc 52 or opening 57 in disc 50 to vary the rate of flowbetween the two directions of flow between the bladders 53 and 46. Itshould, however, be clear that other means can be provided for varyingthe resistance to the movement of the shaft in either direction such asutilizing a stiffer rubber in a bladder 53 than in the bladder 46 sothat when bladder 52 is forced downward the bladder 53 will curl inwardproviding a certain amount of resistance in one direction which may bedifferent from the resistance to the movement of the shaft 42 in theopposite direction. It should also be clear that, in this embodiment asin the other embodiments, the casings can be teflon lined to preventwear and abrasion on the bladders thereby providing longer life to theshock absorbet.

FIG. 9 is a shock absorber in accordance with FIG. 6 except for theabsence of the tube 54 passing therebetween and which relied solely onthe difference of the stiffness of the rubber and the different designsbetween the bladders 60 and 61 to provide the variation between themotion in each direction. This shock absorber, similar to the embodimentof FIG. 6, has the same casing 41 with shaft 42 feeding through a donutshaped bladder 62 and connected to a large disc 50 which is in turnconnected by means of a shaft 51 to a smaller disc 52 and has a lowershaft 44 for connection to the vehicle body.

FIGS. 7 and 8 show yet another embodiment of the present invention,having a casing 65 with a second telescoping case 66 telescoping overcasing 65. Casing 65 has a shaft 67 with a vehicle connector 68 attachedthereto and an upper shaft 70 connected to the upper telescoping portion66. A central disc 71 is connected to the outer telescoping portion 66by use of members 72, and is also connected by means of hollow shafts 73and 74 to discs 75 and 76 respectively. Disc 77 rides against a bladder77 while disc 76 rides against a bladder 78 located in the casing 65. Aslot 80 in the side of the casing 65 allows the members 72 to bethreaded through the casing 65 and to slide in the slot 80. The hollowportion 81 passing through the shafts 73 and 74 allowing a tube 82 topass therethrough, interconnecting tubes 77 and 78. This embodimentanticipates a variation in the resistance in the rubber portions and thebladders 78 and 77 to provide the differential between the directions oftravel of the shaft 70. This embodiment eliminates the use of theannular bladder of 5 the other embodiments while allowing the bladdersystem to be utilized in a tubular shock absorber having one elementtelescoping over a second casing element.

It should be realized at this point that a shock absorber has beenprovided which has eliminated the need for fluid type seals in a systemhaving fluids being totally sealed in. A system has also beenillustrated having means for adding or deleting fluid and varying theflow of the fluid between a pair of bladders to provide additionalcontrols in the dampening action of the shock absorber. However, itshould be clear to those skilled in the art that other embodiments arecontemplated and that this invention is not to be construed as limitedto the particular formsdisclosed herein since these are to be regardedas illustrative rather than restrictive.

I claim:

1. A vehicle shock absorber comprising in combination:

a. casing means having two end portions;

b. connecting means connected to said casing for attaching said casingto a vehicle;

c. a pair of flexible bladders, each said bladder being located in oneend of said casing, and each said bladder being at least partiallyfilled with fluid;

d. movable bladder engaging means dividing said pair of bladders andadapted to move against either said bladder, said movable bladderseparating means being connected to said vehicle in a manner that thewheel suspension of said vehicle will move said bladder engaging meansrelative to said casing means when said wheel suspension is placed inmotion; and one said bladder having a greater resistance to the movementof the bladder separating means than the other said bladder, wherebydampening in each direction is substantially different; and

e. said bladder engaging means having a pair of connected disc members,one said disc being smaller than the other said disc.

2. The apparatus in accordance with claim 1 in which the casing meanshas an interior portion thereof coated with Teflon.

3. The apparatus in accordance with claim 1 in which bladder connectingmeans passes through said bladder engaging means to operatively connectsaid bladders.

4. The apparatus in accordance with claim 1 in which a shaft connectssaid bladder engaging means with said vehicle. I

5. The apparatus in accordance with claim 4 in which one said flexiblebladder is annular shaped and surrounds the said shaft.

6. The apparatus in accordance with claim 4, in which said smaller discmember is adapted to curl one said bladder inward upon said separatingmeans being driven thereagainst.

7. The apparatus in accordance with claim 6 in which said connectingmeans includes a telescoping member telescoping over said casing.

1. A vehicle shock absorber comprising in combination: a. casing meanshaving two end portions; b. connecting means connected to said casingfor attaching said casing to a vehicle; c. a pair of flexible blAdders,each said bladder being located in one end of said casing, and each saidbladder being at least partially filled with fluid; d. movable bladderengaging means dividing said pair of bladders and adapted to moveagainst either said bladder, said movable bladder separating means beingconnected to said vehicle in a manner that the wheel suspension of saidvehicle will move said bladder engaging means relative to said casingmeans when said wheel suspension is placed in motion; and one saidbladder having a greater resistance to the movement of the bladderseparating means than the other said bladder, whereby dampening in eachdirection is substantially different; and e. said bladder engaging meanshaving a pair of connected disc members, one said disc being smallerthan the other said disc.
 2. The apparatus in accordance with claim 1 inwhich the casing means has an interior portion thereof coated withTeflon.
 3. The apparatus in accordance with claim 1 in which bladderconnecting means passes through said bladder engaging means tooperatively connect said bladders.
 4. The apparatus in accordance withclaim 1 in which a shaft connects said bladder engaging means with saidvehicle.
 5. The apparatus in accordance with claim 4 in which one saidflexible bladder is annular shaped and surrounds the said shaft.
 6. Theapparatus in accordance with claim 4, in which said smaller disc memberis adapted to curl one saId bladder inward upon said separating meansbeing driven thereagainst.
 7. The apparatus in accordance with claim 6in which said connecting means includes a telescoping member telescopingover said casing.